The objective of the invention is a device and a method for punching a planar object using a sewing machine.
Sewing machines generally comprise a stand, from which laterally a lower arm and an upper arm project. The end section of the upper arm is embodied as a machine head, with a needle bar, which can move up and down, and a sewing foot projecting at its bottom. At the lower arm, which serves as a support for the fabric, an exchangeable needle plate is arranged underneath the machine head. It comprises a piercing opening for the sewing needle and recesses for the feed dog of a feeder, which periodically advances the fabric during the sewing process, coordinated with the movement of the needle bar, in a sewing direction perpendicularly in reference to the motion of the needle bar. The feed motion by the feeder can be deactivated in most sewing machines. The motion of the fabric in the sewing plane can alternatively also occur e.g., in a purely manual fashion. Many sewing machines are additionally embodied to connect an embroidery module. Here, the fabric is stretched in a tambour frame, which can be displaced in two orthogonal directions of the sewing plane. When embroidering depending on the predetermined embroidery pattern the tambour frame is displaced into the respectively required position by two independent drives for each of the stitches to be formed.
In an appropriate embodiment, as an alternative to sewing needles, other tools can also be connected to process a planar object connected to the sewing machine. For example, it is known from the European patent application EP2221409A1 to fasten a tool, e.g., a textile pen, via a fastening device to the sewing foot rod of the sewing machine and to use this tool, instead of a sewing needle, to process a textile or non-textile planar object. A fastening device for decorative elements, such as rhinestones or sequins, is known from DE102010020623A1, which can be connected to a sewing machine and influenced by said sewing machine. The decorative elements are stored in magazines or on support tapes and are individually applied by the fastening device on the planar object at the predetermined position. The planar object may for example represent an adhesive transfer film. The decorative elements are first applied in the respective arrangement on the transfer film, where they temporarily are adhered, and they are subsequently transferred via heat to a textile planar object.
Furthermore, EP2172585A1 discloses a rotary device for a cutting needle, which can be fastened at the needle bar. Using this rotary device the alignment of the blade of the cutting needle can be adjusted in reference to the fabric so that the cutting angle can be adjusted to the contours on the planar object to be cut out.
Such devices, which can be connected to the sewing machine, allow processing a planar object with different technologies. When a planar object is stretched in a tambour frame its relative position and alignment at the tambour frame can be maintained for several processing steps. It is also possible to subsequently process several different planar objects in one or more processing steps. Here, the relative coordinates used in reference to the tambour frame can be adjusted to each other for every work piece during processing.